Monday, September 3, 2007

Animal eyes inspire new technology part-2

One of the most well-known examples of technology imitating biology involves the compound eyes of the lobster. In the 1960s, researchers figured out how to build x-ray telescopes, which capture incoming x-rays and focus them as they bounce off specialized mirrors.

In 1979, it became clear that nature had been way ahead of the game. Researchers discovered that natural selection had endowed lobsters with pretty much the same type of system for vision millions of years ago.

Researchers are also learning optics lessons from animals that, until recently, we didn’t even think had vision-like abilities at all.

Several years ago, scientists discovered that a relative of the starfish called the brittlestar has arrays calcite crystals throughout its skeleton that correct certain light-distorting effects and send vision-related signals to the nervous system. These crystals, which collectively form a system akin to a compound eye, may offer new leads for improving optical fibers or developing optical computers.

Another curious creature, the beetle Melanophila acuminate, can detect forest fires around 80 kilometers away. Female beetles lay eggs in burnt trees, and they detect the fires using specialized pit organs tuned to a specific frequency of infrared light. Researchers are now working on developing new materials that behave similarly to use for detecting heat.

One of the main reasons that researchers are making such progress in imitating living eyes is that they are able to build them out of flexible synthetic polymers or plastics. Living eyes and other body parts are made of naturally occurring, chain-like molecules, so the use of synthetic polymers makes plenty of sense.

In conventional optoelectronics, researchers use flat wafers and create patterns on top of them. A number of recently developed techniques for processing polymers, including rapid templating and thin film multilayers have made it possible to make complex and curved shapes. Lee and other researchers make polymer structures from three-dimensional molds, allowing them to produce curved structures and stretchy components for their devices.

“All of our devices are fabricated with soft-state polymers, not solid-state semiconductors, metal or glass. It’s a completely different way of creating complex integrated system with a precision optical alignment in three dimensions using polymers,” Lee said.